Pressure-fluid-actuated tool



W. H. KELLER.

PRESSURE FLUID ACTUATED TOOL.

APPLICATION FILED APR.27.1918.

1,329,774, Patented lFeb. 3, 1920.

WILLIALVI H.

t INEUMATIC TL illlllPAN, {ill/AEL,

i Application filed April 27,

To all whom t may concern.'

Be it known that l, lILLIA-M H. KELLER, a citizen o'i the United States, residing at Grand Haven, in the county of Ottawa and State of Michigan, have invented certain new and useful improvements in Pressure- Fluid-Actuated Tools, of which the following is a specification.

The invention relates to -pressurediuidactuated tools, and the general object there ot is to provide a tool ot improved construction and arrangement `which may be manufactured at a minimum cost.

- A more specific object oit the invention is to provide valve mechanism, of improved construction, for pressure -fluidactuated tools.

A further object of the invention is to provide improved valve mechanism for tools of the so-called one-piece type.

The objects ol the invention thus generally stated, togetherrwith other and ancillary advantages, are attained by the construction and arrangement illustrated in the accompanying drawings forming part hereof, in which Figure l. is a longitudinal central sectional view through, pneumatic hammer embodying the features ot the in* vention, showing the valve in one position. Fig. :2 is a 'fragmentary longitudinal sectional view showing the valve in another position.

The tool` comprises a cylinder 1, a handle 2 mounted upon therear end oiu the cylinder, a piston 3 operable within the cylinder, and valve mechanism et mounted within the rear end ci the cylinder and arranged to control the movements of the piston 3.

The cylinder 1 is preferably made outa round piece oi metal of substantially uniform external diameter throughout, so that it may be made ot bar stock or steel tubing cut to size. T he usual rivet set 5 is suitably retained in the forward end oi the cylinder and the valve mechanism i l is mounted within the rear end oi the cylinder which is closed by means ol a screw plug 6 which may be readily removed when desired.

The handle 2 is preferably of the open type comprising a hand portion T and a head portion 8 connected together by a single neck portion Said head portion 8 has a longitudinal opening 10 therein oit' such diameter that the head will lit tightly upon the rear end ot the cylinder, and after Specification of Letters Patent.

PATENT QFFICE,

, 03? GRAND HAVEN, ICEGaN, ASSIGNOR T0 KELLER .PRESEURE-FLID-AGTUATED TGL.

Patented Feb. 3,

M318. Serial N0. 23110605 they have been completely machined and finished, the handle and cylinder are permanently secured together in anysuitable manner as bywelding, bijazingf or yshrinking- The piston 3 is of uniform diameter throughout its length and is arranged to be inserted and removed through the forward end of the cylinder? by merely removing the rivet set 5. Should thepiston become tast in the cylinder for any reason, which frequently happens'in use, the yscrewy plug 6 may be readilyremoved and a suitable tool inserted froinfthe rear end of the cylinder to loosen the piston and remove it from the cylinder.

Ilhe valve mechanisme of the hammer, v-,f'hichfis mounted withinthe rear end of the cylinder l, comprises a valve casing lland a tubular valve member 12. The casing is tubular in form andinounted in an enlarged bore 11n in the cylinder forming a shoulderl 11b against which the inner end of the'casing is held by the screw plug 6. The valve member is also tubular yin form and is slidable in the casing and arranged'to receive the piston 3.` Said valve casing isl made in `tivo sections tor two'rea'sons. The first is that it may be more cheaply manufactured, as hereinafter set `orth, andthesecond is that it may be readily inserted into or removed ;trom the cylinder, lafter the handle and cylinder have been permanently secured together-into a one-'piece structure, without unduly lenggthening the hammer by extending the hand or grasping portion 7 ofthe handle rearwardly' a suicient'distance to Y' )e1-mit an integral valve casino to ass between said Gras ine' ort-ion and the rear end t: 2D y H of the cylinder.' j

At its rear end the valve casino' has a series of ports 13 opening into the rear end of the cylinder and each leading from a passageway 14 in the casing` which in turn communicates at all times through a duct 15 and an annular groove 16 in the screw plug 6 with a passageway suitably formed vin the handle 2. Said passageway in the handle is connected with a sourcef pressure fluid supply and is controlled by a manually operable throttle valve 17. Preferably the passageway is formed byl plurality of drilled passageways 18, 18a` and 18", the passageways 18n and 18b being connected by an angular passageway 18c formed in a plug 184 which isprovided to close the openings left in the handle by the operation o/fdri'll-YV ing the passageway 18a. A plug 18e is also provided in the head of the handle to close the opening left by drilling the passageway 18".

The valve member 12 is arranged to control the admission of pressure fluid into the cylinder through the ports 13. Said valve member is preferably tubular in forni, having a uniform internal diameter throughout its length equal to the bore of the cylinder. OnY its outer periphery said member is provided with a plurality of peripheral flanges 19 and 19u, and 20 and 20a, spaced apart and bearing upon the inner surface of the valve casing 11. The flanges 19 and 19a are made somewhat larger than the flanges Q and 20a so as to have a greater area, for

a purpose to be hereinafter set forth, and

the inner surface of the valve casing is correspondingly made of different diameters to conform to the sizes of the flanges. Thus in the manufacture of the valve mechanism it becomes necessary to make the valve casing with a plurality of different internal diameters 1Q, 12b and 12C.. the intermediate diameters 12a and 12b being larger than the diameters 12C at the ends of the casing. It is difiicult, however, to bore and grind such relatively large intermediate diameters, and I therefore form the valve casing` in two separate sections each having only one of the intermediate diameters and an end diameter. It will be seen that each dier-eter of cach of the sections readily accessible to a tool inserted into the section. Preferably one of the sections is rahbeted as at 9.1 to receive the end of the-adjacent section.

rihe rear end of said valve member is arranged to slide over the inner ends of the ports 13, and when the valve member is in its foremost position, as shown in Fig. L pressure fluid is admitted into the rear end of the cylinder and the piston is driven forwardlv therein. The valve member is held in such position until the piston approximately reaches the forward end of the cylinder. The means for thus holding the valve member in its foremost position comprises a port 22 in the rear end of the valve casing and a series of ports 22a in the valve member. The port `22 is in constant communication with the passageway 14 in the casing and thus with the pressure fluid supply, and the ports 22@ communicate with the cylinder when the piston travels forwardly in the cylinder. Said ports thus admit the pressure fluid to the rear surface of the flange 20a, and the pressure fluid bearing thereon s i'ves to hold the valve member inY its foreitposition until the piston 3 initsy forward travel passes a pair of p opening into the eylinder substantially' centrally thereof. Said ports communicate with a longitudinal passageway 24 extending rear-1A wardly in the cylinder, and said passagewau 2a'- in turn communicates with a passageway 25 which admits pressure fluid to the forward side of the peripheral flange 19 of the valve member. As above stated, the flange 19 is made larger than the flange 20 on the rear end of the valve member, so that the pressure area formed thereby is greater than that formed by the ange 20a. Accordingly when the pressure fluid is admitted into the ports 9.3 by the passage of the piston forwardly in the cylinder it acts to shift the valve meniber rearwardly.

,Vhile the piston is traveling forwardly in the cylinder, air in the forward end thereof is permitted to escape to the atmosphere by means of the passageway 26 leading from the forward end of the cylinder rearwardly to the valve casing, where it communicates with a passageway 27 which opens into a groove 28 formed between the flanges 19 and 29 on the valve member (Fig. i). Said grooif'e 28 in turn is arranged to discharge into groove 29 in the valve casing and thence into a duct leading through the valve casing, the cylinder` and the handle te the atmosphere.

The valve member having been shifted rearwardly to the position shown in Fig. 2, pressure fluid is admitted to the forward end of the c 7linde; to drive the piston rearwardly therein. To this end aV passageway 31. leading from one of the pressure iluid supply ducts 15 in the screw-plug 6 discharges pressure fluid into the groove 28 bet veen the flanges 19Fl and 20 on the valve member. This groove now communicates with the passageway 27 in the valve casu the -`groove 29 in the valve casingl leadin te the exhaust duct 30 having been -f oser-' by the valve inen'iber when moved rearwardly, and the forward end of the passageway 31 having been opened by the valve member during such rearward movement thereof. Pressure fluid is thus admitted to the forward end of the cylinder and the piston is driven rearwardly in the cylinder.

As the pieten moves i'ea-i".\'ardly in the cylinder, the pressure fluid therein is permitted to eXhaust from in front of the piston through a series of ducts in the for ward end of the valve casing, the inner ends of which ducts have been oiriened by the rearward ni.o*e1neiit of the valve member. Said ducts are arranged to discharge into the exhaust duct 3G leading to the atmosphere. deflector over the exhaust duct 250 for directing the exhaust pressure fluid forwardly rather than radially of the cylinder.

ifhen the piston in its rearward travel passes the ports in the cylinder, the flow of pressure fluid heilig cut ofl from the forward pressure area "on the flange 19: ofthe valve member, enables the pressure fluid actingl upon the rear `pressure area on the Iiange 20 to again shift the valve member forwardly so as to admit pressure 'fluid into the rear end of the cylinder. In this position the valve membei` also cuts olf the flow of pressure fluid through the passageway 31 to the forward end of the cylinder, and establishes communication between the forward end of the cylinder and the exhaust duct 30. The parts are thus in position for another cycle of operation.

If additional pressure is needed to shift the valve member rearwardly, a restricted passageway 34 may be provided in the valve casing, which passageway communicates constantly with the source of pressure fluid supply and conducts the pressure Huid to the forward pressure area on the [lange 19 of the valve member. This flow of pressure fluid, however, is not suiiicient to interfere with the forward shifting of the valve member when the flow of pressure fluid through the ports 23 is cut ofi'.

It will be understood that the piston in its rearward travel, after passing the exhaust ducts 32, builds up sufficient pressure in the rear end of the cylinder to cushion the piston in its rearward movement.

It will be apparent that the screw plug G serves to clamp the separate sections of the valve casing together within the rear end of the cylinder so that it forms in effect an integral casing. At the same time the casing, as well as the valve member, may be readily removed from the cylinder without undulv lengthening the hammer by extending the hand or grasping portion of the handle rearwardly. `In this operation of removing the valve mechanism it is only necessary to unscrew the plug 6, and the rear section of the casing is Vfirst removed. Thereupon the valve member may beremoved and finally the forward section of the valve casing. This construction lends itself readily to a hammer in which the cylinder and handle .form a one-piece structure, and at the same time the valve casing may be more cheaply manufactured by reason of the increased facility with which the parts may be separately machined.

`The method set forth of forming the passageway through the handle is advantageous in that all danger of restricting the passageway bv forming the handle after the passageway has been drilled therein. is eliminated.

While I have herein set forth the invention with considerable particularitv and especially the valve structure. it will beunderstood that the invention is not thus limited but that the structure. set forth is merely illustrative of a preferred embodiment of the invention.

il. A vpressure-fluidactuated ltool having, in combination, a cylinder and a handle inseparably formed into a one-piece structure, 'said handle having a transverse handf'portonfspniced, a short distance rearwardly `of the cylinder, a piston operable in the cylinder, and valve mechanism for controlling the piston, comprising avalve casing mounted within the cylinder, said casing being of a length greater than the space between the cylinder and said transverse hand portion of the handle and formed in separate sections so as to be removable from the rear end of the cylinder with the handle in position thereon.

2. A pressure-{inid-actuated tool comprising, in combination, a cylinder, a khandle comprising a tubular portion constructed to lit snugly upon the rear end of the cylinder,

and a transverse hand portion rigid with said tubular portion but spaced a short distance rearwardly thereof, said tubular portion of the handle being secured onto the rear end of the cylinder as by welding so as to be permanently connected therewith in a one-piece structure, a piston operable in the cylinder, and valve mechanism for controlling the movements of the piston including a tubular casing mounted in the rear end of the cylinder, said casing being formed in' separate sections each of a length not greater than the space between the handle and the cylinder so as to be removable from the cylinder with the handle in position thereon.

3. A pressure-luid-actuated tool comprising, in combination, a cylinder and a handle inseparably formed into a one-piece structure, said handle having a transverse hand portion spaced'a short distance rearwardly of the cylinder, a piston operable in the cylinder, valve mechanism for controlling the piston comprising a valve casing and a tubular valve member operable in the casing in axial alinement with the cylinder and adapted to receive said piston in the movements thereof, and means for closing the rear end of said cylinder and clamping said valve casing in position therein, said casing being formed in separate sections each of a length not greater than the distance between the cylinder and said transverse end portion of the handle, and said valve member being adapted to be removable from the rear end of the cylinder after the rearmost section of the casing has been removed.

4l. A pressure-fiuid-actuated tool comprising, in combination, a cylinder and a handle inseparably formed `into a one-pieceV structure, said handle having a transverse hand portion spaced a short distance rearwardly of the cylinder, a piston operable in the cylinder, valve mechanism for controlling the piston' comprising a valve casing made in two relatively short sections of substantially equal length and a tubular valve member operable in said casing, and means for closing the rear end of the cylinder and clamping said valve casing in position therein, said casing and Valve membel1 being constructed to permit the removal from the real' end of the cylinder, VWith the handle thereon, first of the rearmost section of the casing, then of the valve member, and {inail}v1 1C of the other section of the casing.

In testimony whereof, I have hereunto set my hand.

WILLIAM H. KELLERA 

